Being "in touch" has become increasingly important for some people, i.e., doctors, business executives, attorneys, etc., who have a strong need to be reached wherever they are. Many of these people have a telephone for business, a telephone for home, a mobile cellular telephone for the car and/or a transportable telephone that can be carried around when not near one of the other telephones. Additionally, some professionals have multiple offices with a telephone in each office. Some work at home in conjunction with an office at a business location for when they are "on premises", with at least one telephone at each location. All of these telephones generally have different telephone numbers and are frequently on different local offices with different prefixes. This requires the caller to know or look up multiple telephone numbers, and frequently to make multiple calls in order to reach a person.
While there are several telephone equipment features and telephone company services designed to ease the problem of multiple telephone numbers, they do not solve all the problems. For example, call forwarding provides call redirection from one telephone to another. However, once the subscriber activates call forwarding, he or she cannot answer the primary telephone until the feature is deactivated. Additionally, calls can only be forwarded to one telephone, so that the user must know where he or she is going to be in order to forward calls effectively. Without remote activation, subscribers must turn on call forwarding from their primary telephone.
A second attempt to solve this problem requires the addition of expensive customer premises equipment connected to the primary telephone and either a second telephone line or three-way calling. In this system, when a call comes in, the system sets up a three-way call to a pre-programmed telephone number, and either simultaneously alerts the attached telephone and the remote telephone or alerts the remote telephone after a predetermined number of rings. The system determines whether the attached telephone or the remote telephone answers first. If the attached telephone answers first, the system terminates the connection to the remote telephone. If the remote telephone answers first, the system bridges the incoming call to that telephone or, for three-way calling, simply drops off the connection. This system is limited in the number of other telephones that the may be alerted, and involves installing and programming customer premises equipment that occupies space at or near the customer's telephone, and requires an additional line or coordination with three-way calling.
Some central offices have the capability to alert two telephones in response to an incoming call, and terminate the incoming call to the first of the telephones from which an off-hook signal is detected. This system is limited in that both of the alerted telephones must be connected to the same central office.
Therefore, a problem in the art is that there is no low cost, network based solution to the problem of alerting a plurality of telephones connected to more than one central office for a single incoming call.